Multi-panel skirt system for cargo enclosures

ABSTRACT

A preferred multi-panel skirt system for a cargo enclosure includes two pair of forward and aft skirt panels with each pair located on an opposite lateral sides of the enclosure. In each pair, the forward skirt panel extends along the bottom wall generally in the lengthwise direction between a leading edge and a trailing edge, which is located adjacent to and aligned with or positioned laterally inboard of a lateral side edge of the enclosure. An aft skirt panel extends along the bottom wall generally in the lengthwise direction between a leading edge and a trailing edge aft of the forward skirt panel, which trailing edge is located adjacent to and aligned with or positioned laterally inboard of the lateral side edge of the enclosure. The leading edge of the aft skirt panel is positioned laterally inboard of the trailing edge of the forward skirt panel.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a U.S. nonprovisional patent application of,and claims priority under 35 U.S.C. § 119(e) to, U.S. provisional patentapplication 62/798,807, filed Jan. 30, 2019, which provisional patentapplication is incorporated by reference herein.

COPYRIGHT STATEMENT

Any new and original work of authorship in this document—including anysource code—is subject to copyright protection under the copyright lawsof the United States and other countries. Reproduction by anyone of thisdocument as it appears in official governmental records is permitted,but otherwise all other copyright rights whatsoever are reserved.

BACKGROUND OF THE INVENTION

The invention generally relates to skirt systems and fairings for cargoenclosures.

An ongoing effort to reduce drag in vehicular structures and associatedcargo enclosures is of great importance as fuel economy becomes anincreasingly large consideration in the overall design of a vehicle orits associated cargo enclosure. As the drag increases, the amount offuel needed to move the vehicle also increases due to the greater energyrequired to overcome the drag. For instance, it has been stated that fora vehicle traveling at 70 mph, about 65% of the total fuel consumptionof the vehicle's engine is used to overcome drag. Therefore, even asmall reduction in the drag experienced by a vehicle traveling athighway speeds can result in a significant improvement in fuel economy.

A typical drag-reducing technique for heavy-duty vehicles, such astractor-trailers (also known as semi tractors, tractors, class 8 longhaul trucks, transfer trucks, 18-wheelers, semis, etc.), is to install askirt along each side of the undercarriage of the trailer. Aconventional skirt comprises an elongated panel that is typicallyconfigured to extend continuously across the gap defined between atrailer's landing gear and rear wheels. The skirt is generally designedto substantially block an airflow from flowing underneath the trailer,thereby preventing high energy air from contacting the rear wheels andcausing a significant amount of drag on the vehicle.

While conventional skirt designs do provide some drag-reducingadvantages for a heavy-duty vehicle, such designs still have severaldrawbacks. For example, when a cross-flow is directed across the trailerand flows between the skirts positioned along either side of theundercarriage at the front end of the trailer, the continuous profile ofthe opposed skirts traps the airflow therebetween. As a result, thetrapped airflow is directed towards and into the rear wheels of thetrailer, thereby resulting in an increase in the amount of drag on thetrailer. Moreover, given the continuous profile of conventional skirts,such skirts are often subject to damage due to impacts with the adjacenttravel surface or other impediments.

Accordingly, a need exists for an improved skirt design and relatedskirt system to provide drag reduction for a cargo enclosure that isincluded within or configured to be coupled to or hauled by a vehicle.

SUMMARY OF THE INVENTION

The invention includes many aspects and features. Moreover, while manyaspects and features relate to, and are described in, the context oftractor-trailers and cargo enclosures related thereto, the invention isnot limited to use only in such context, as will become apparent fromthe following summaries and detailed descriptions of aspects, features,and one or more embodiments of the invention.

Accordingly, in one aspect a cargo enclosure for storing cargo includesa multi-panel skirt system installed relative to a bottom wall of thecargo enclosure. The multi-panel skirt system is generally configured toreduce the overall amount of drag occurring on the cargo enclosure.

In another aspect, a cargo enclosure for storing cargo comprises: (a) atop wall; (b) front and rear walls; (c) first and second side wallsextending between the front and rear walls in a lengthwise direction ofthe cargo enclosure; (d) a bottom wall extending between the front andrear walls in the lengthwise direction and between the first and secondside walls in a lateral direction of the cargo enclosure, the first sidewall intersecting the bottom wall at a first lateral side edge of thecargo enclosure, the second side wall intersecting the bottom wall at asecond lateral side edge of the cargo enclosure, with the top wall, thefront and rear walls, the side walls, and the bottom wall enclosing acargo space of the cargo enclosure; and (e) a multi-panel skirt systeminstalled or otherwise secured to the bottom wall. The multi-panel skirtsystem comprises: a first forward skirt panel extending along the bottomwall generally in the lengthwise direction between a leading edge and atrailing edge, the trailing edge of the first forward skirt panel beinglocated adjacent to and aligned with or positioned laterally inboard ofthe first lateral side edge of the cargo enclosure; and a first aftskirt panel extending along the bottom wall generally in the lengthwisedirection between a leading edge and a trailing edge aft of the firstforward skirt panel relative to a forward travel direction of the cargoenclosure, the trailing edge of the first aft skirt panel being locatedadjacent to and aligned with or positioned laterally inboard of thefirst lateral side edge of the cargo enclosure. The first aft skirtpanel extends laterally inboard as the first aft skirt panel extends inthe lengthwise direction from its trailing edge to its leading edge suchthat the leading edge of the first aft skirt panel is positionedlaterally inboard of the trailing edge of the first forward skirt panel.

In a feature, the leading edge of the first forward skirt panel ispositioned further laterally inboard than the trailing edge of the firstforward skirt panel. The cargo enclosure preferably defines a lengthwisecenterline extending in the lengthwise direction that is centeredrelative to the first and second lateral side edges in the lateraldirection, and the leading edge of the first forward skirt panel ispositioned a lateral distance from the lengthwise centerline that isless than a lateral distance defined between the leading edge of firstforward skirt panel and the first lateral side edge of the cargoenclosure.

In a feature, the trailing edge of the first forward skirt panel ispositioned forward of the leading edge of the first aft skirt panelrelative to the forward travel direction for the cargo enclosure suchthat a lengthwise gap is defined between the first forward and aft skirtpanels in the lengthwise direction.

In a feature, the trailing edge of the first forward skirt panel ispositioned aft of the leading edge of the first aft skirt panel relativeto the forward travel direction for the cargo enclosure such that thefirst aft skirt panel overlaps the first forward skirt panel in thelengthwise direction, and a transverse gap, extending between thetrailing edge of the first forward skirt panel and the leading edge ofthe first aft skirt panel, defines an air vent.

In a feature, the first forward skirt panel defines a compound lateralprofile between its leading and trailing edges. The first forward skirtpanel preferably includes a first lengthwise section and a secondlengthwise section, a lateral profile of the first lengthwise sectiondiffering from a lateral profile of the second lengthwise section suchthat the first forward skirt panel extends further inboard along thesecond lengthwise section than along the first lengthwise section. Thecargo enclosure also preferably includes landing gear installed orotherwise secured to the bottom wall and the first forward skirt paneldefines a transition point at which the lateral profile of the firstlengthwise section transitions to the lateral profile of the secondlengthwise section, the first forward skirt panel being installedrelative to the landing gear such that the transition point is locatedadjacent to an aft end of the landing gear.

In a feature, the first aft skirt panel defines a compound lateralprofile between its leading and trailing edges.

In a feature, the first aft skirt panel includes a first lengthwisesection and a second lengthwise section, a lateral profile of the firstlengthwise section differing from a lateral profile of the secondlengthwise section such that the first aft skirt panel extends furtherinboard along the second lengthwise section than along the firstlengthwise section.

In a feature, each of the first forward and aft skirt panels defines acompound lateral profile between its leading and trailing edges.

In another aspect, a multi-panel skirt system for a cargo enclosurecomprises: (a) a first forward skirt panel configured to extend along abottom wall of the cargo enclosure generally in the lengthwise directionof the cargo enclosure between a leading edge and a trailing edge of thefirst forward skirt panel, with the trailing edge of the first forwardskirt panel located adjacent to and aligned with or positioned laterallyinboard of a first lateral side edge of the cargo enclosure; and (b) afirst aft skirt panel configured to extend along the bottom wall aft ofthe first forward skirt panel generally in the lengthwise directionbetween a leading edge and a trailing edge of the first aft skirt panelrelative to a forward travel direction of the cargo enclosure, with thetrailing edge of the first aft skirt panel being located adjacent to andaligned with or positioned laterally inboard of the first lateral sideedge of the cargo enclosure. The first aft skirt panel is configured toextend laterally inboard as the first aft skirt panel extends in thelengthwise direction from its trailing edge to its leading edge suchthat the leading edge of the first aft skirt panel is positionedlaterally inboard of the trailing edge of the first forward skirt panel.

In a feature, the leading edge of the first forward skirt panel isconfigured to be positioned further laterally inboard than the trailingedge of the first forward skirt panel.

In a feature, the multi-panel skirt system further comprises a secondforward skirt panel and a second aft skirt panel, the second forwardskirt panel configured to extend along the bottom wall in the lengthwisedirection between a leading edge and a trailing edge thereof, the secondaft skirt panel configured to extend along the bottom wall in thelengthwise direction between a leading edge and a trailing edge thereofaft of the second forward skirt panel relative to the forward traveldirection of the cargo enclosure.

In a feature, the multi-panel skirt system further comprises a secondforward skirt panel and a second aft skirt panel, the second forwardskirt panel extending in the lengthwise direction between a leading edgeand a trailing edge and being installed along the bottom wall, thesecond aft skirt panel extending in the lengthwise direction between aleading edge and a trailing edge and being installed along the bottomwall aft of the second forward skirt panel relative to the forwardtravel direction of the cargo enclosure.

In a feature, the multi-panel skirt system is configured to define alateral gap between the first and second forward skirt panels in thelateral direction of the cargo enclosure.

In a feature, the first and second forward skirt panels are configuredto create a converging lateral gap therebetween as the first and secondforward skirt panels extend in the forward travel direction towardstheir respective leading edges.

The first forward skirt panel may serves as an upwind forward panel andthe second forward skirt panel serves as a downwind forward panel whenthe cargo enclosure is subjected to a cross-flow directed from its firstlateral side edge towards its second lateral side edge, and when thecross-flow is directed through the lateral gap defined between the firstand second forward skirt panels at their leading edges, the leading edgeof the upwind forward panel is configured to generate a vortex inassociation with a first portion of the cross-flow directed through thelateral gap while a second portion of the cross-flow is configured to becaptured along an inner surface of the downwind forward panel.Furthermore, the second portion of the cross-flow preferably exits fromunderneath the cargo enclosure via an air vent defined between thedownwind forward panel and the second aft skirt panel.

In a feature, the trailing edge of the second forward skirt panel isconfigured to be spaced apart from the leading edge of the second aftskirt panel such that an air vent is defined between the second forwardand aft skirt panels.

In a feature, the multi-panel skit system consists of two pairs of skirtpanels, each pair consisting of a forward skirt panel and an aft skirtpanel.

In a feature, each panel skirt is configured to create vortexes at itsleading edge from a cross-wind passing thereby.

In a feature, each skirt panel comprises means for generating a vortexwhen an airflow is directed past the leading edge thereof. The means maycomprise a sharp inboard lateral profile of a leading section of theskirt panel; the means may comprise a camber or shape of a leadingsection of the skirt panel; or the means may comprise both a sharpinboard lateral profile of a leading section of the skirt panel, and acamber or shape of a leading section of the skirt panel.

In another aspect, a kit includes a multi-panel skirt system forinstallation on a cargo enclosure in accordance with one or morepreferred embodiments of the invention.

In another aspect, a method includes installing a multi-panel skirtsystem on a cargo enclosure in accordance with one or more preferredembodiments of the invention.

In another aspect, the multi-panel skirt system comprises a firstforward skirt panel and a first aft skirt panel. The first forward skirtpanel extends in the lengthwise direction between a leading edge and atrailing edge and is installed along the bottom wall. The trailing edgeof the first forward skirt panel is located adjacent to and is alignedwith or positioned laterally inboard of the first lateral side edge ofthe cargo enclosure. The first aft skirt panel extends in the lengthwisedirection between a leading edge and a trailing edge and is installedalong the bottom wall aft of the first forward skirt panel relative to aforward travel direction of the cargo enclosure. The trailing edge ofthe first aft skirt panel is located adjacent to and is aligned with orpositioned laterally inboard of the first lateral side edge of the cargoenclosure. The first aft skirt panel preferably defines a profile thatextends laterally inboard as the first aft skirt panel extends in thelengthwise direction from its trailing edge to its leading edge suchthat the leading edge of the first aft skirt panel is positionedlaterally inboard of the trailing edge of the first forward skirt panel.

In another aspect, a multi-panel skirt system includes pairs of forwardand aft skirt panels supported relative to a bottom wall of the cargoenclosure. Specifically, first forward and aft skirt panels areinstalled on the bottom wall on a first lateral side of the enclosureand second forward and aft skirt panels are installed on the bottom wallon a second lateral side of the enclosure.

In another aspect, a multi-panel skirt system for a cargo enclosurecomprises one or more skirt panels configured in accordance with one ormore of the skirt panel embodiments described herein.

In addition to the aforementioned aspects and features of the invention,it should be noted that the invention further encompasses the variouslogical combinations and subcombinations of such aspects and features.Thus, for example, claims in this or a divisional or continuing patentapplication or applications may be separately directed to any aspect,feature, or embodiment disclosed herein, or combination thereof, withoutrequiring any other aspect, feature, or embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more preferred embodiments of the invention now will be describedin detail with reference to the accompanying drawings, wherein the sameelements are referred to with the same reference numerals.

FIG. 1 illustrates a side view of one embodiment of a cargo enclosureconfigured in accordance with a preferred embodiment of one or moreaspects and features of the invention, particularly illustrating thecargo enclosure coupled to a tractor and including various skirt panelsof one embodiment of a multi-panel skirt system installed relative to abottom side of the enclosure;

FIG. 2 illustrates a bottom view of the cargo enclosure and tractorshown in FIG. 1, particularly illustrating the relative positioning ofthe various skirt panels along the bottom side of the cargo enclosure;

FIG. 3 illustrates a front, bottom perspective view of the cargoenclosure shown in FIGS. 1 and 2, particularly illustrating another viewof the relative positioning of the various skirt panels along the bottomside of the cargo enclosure;

FIG. 4 illustrates a rear, bottom perspective view of the cargoenclosure shown in FIGS. 1 and 2, particularly illustrating another viewof the relative positioning of the various skirt panels along the bottomside of the cargo enclosure;

FIGS. 5 and 6 illustrate respective side and bottom views of one of theforward skirt panels of the multi-panel skirt system shown in FIGS. 1-4;

FIGS. 7 and 8 illustrate respective side and bottom views of one of theaft skirt panels of the multi-panel skirt system shown in FIGS. 1-4;

FIG. 9 illustrates a portion of the bottom view of the cargo enclosureshown in FIG. 2, particularly illustrating the positioning of the skirtpanels along the bottom side of the enclosure relative to one anotherand relative to other features of the cargo enclosure;

FIG. 10 illustrates the same bottom view of the cargo enclosure as thatshown in FIG. 9, particularly illustrating the skirt panels whensubjected to a cross-flow across the undercarriage of the enclosure;

FIG. 11 illustrates a similar bottom view of the cargo enclosure as thatshown in FIG. 9, particularly illustrating an alternative embodiment ofthe disclosed skirt panels in accordance with a preferred embodiment ofone or more aspects and features of the invention; and

FIG. 12 illustrates a full side view of the cargo enclosure shown inFIG. 11, particularly illustrating an example of a side profile for theembodiment of the skirt panels shown in FIG. 11.

DETAILED DESCRIPTION OF THE INVENTION

As a preliminary matter, it will readily be understood by one havingordinary skill in the relevant art (“Ordinary Artisan”) that theinvention has broad utility and application. Furthermore, any embodimentdiscussed and identified as being “preferred” is considered to be partof a best mode contemplated for carrying out the invention. Otherembodiments also may be discussed for additional illustrative purposesin providing a full and enabling disclosure of the invention.Furthermore, an embodiment of the invention may incorporate only one ora plurality of the aspects of the invention disclosed herein; only oneor a plurality of the features disclosed herein; or combination thereof.As such, many embodiments are implicitly disclosed herein and fallwithin the scope of what is regarded as the invention.

Accordingly, while the invention is described herein in detail inrelation to one or more embodiments, it is to be understood that thisdisclosure is illustrative and exemplary of the invention and is mademerely for the purposes of providing a full and enabling disclosure ofthe invention. The detailed disclosure herein of one or more embodimentsis not intended, nor is to be construed, to limit the scope of patentprotection afforded the invention in any claim of a patent issuing herefrom, which scope is to be defined by the claims and the equivalentsthereof. It is not intended that the scope of patent protection affordedthe invention be defined by reading into any claim a limitation foundherein that does not explicitly appear in the claim itself.

Thus, for example, any sequence or temporal order of steps of variousprocesses or methods that are described herein are illustrative and notrestrictive. Accordingly, it should be understood that, although stepsof various processes or methods may be shown and described as being in asequence or temporal order, the steps of any such processes or methodsare not limited to being carried out in any particular sequence ororder, absent an indication otherwise. Indeed, the steps in suchprocesses or methods generally may be carried out in various differentsequences and orders while still falling within the scope of theinvention. Accordingly, it is intended that the scope of patentprotection afforded the invention be defined by the issued claim(s)rather than the description set forth herein.

Additionally, it is important to note that each term used herein refersto that which the Ordinary Artisan would understand such term to meanbased on the contextual use of such term herein. To the extent that themeaning of a term used herein—as understood by the Ordinary Artisanbased on the contextual use of such term—differs in any way from anyparticular dictionary definition of such term, it is intended that themeaning of the term as understood by the Ordinary Artisan shouldprevail.

With regard solely to construction of any claim with respect to theUnited States, no claim element is to be interpreted under 35 U.S.C.112(f) unless the explicit phrase “means for” or “step for” is actuallyused in such claim element, whereupon this statutory provision isintended to and should apply in the interpretation of such claimelement. With regard to any method claim including a condition precedentstep, such method requires the condition precedent to be met and thestep to be performed at least once but not necessarily every time duringperformance of the claimed method.

Furthermore, it is important to note that, as used herein, “comprising”is open-ended insofar as that which follows such term is not exclusive.Additionally, “a” and “an” each generally denotes “at least one” butdoes not exclude a plurality unless the contextual use dictatesotherwise. Thus, reference to “a picnic basket having an apple” is thesame as “a picnic basket comprising an apple” and “a picnic basketincluding an apple”, each of which identically describes “a picnicbasket having at least one apple” as well as “a picnic basket havingapples”; the picnic basket further may contain one or more other itemsbeside an apple. In contrast, reference to “a picnic basket having asingle apple” describes “a picnic basket having only one apple”; thepicnic basket further may contain one or more other items beside anapple. In contrast, “a picnic basket consisting of an apple” has only asingle item contained therein, i.e., one apple; the picnic basketcontains no other item.

When used herein to join a list of items, “or” denotes “at least one ofthe items” but does not exclude a plurality of items of the list. Thus,reference to “a picnic basket having cheese or crackers” describes “apicnic basket having cheese without crackers”, “a picnic basket havingcrackers without cheese”, and “a picnic basket having both cheese andcrackers”; the picnic basket further may contain one or more other itemsbeside cheese and crackers.

When used herein to join a list of items, “and” denotes “all of theitems of the list”. Thus, reference to “a picnic basket having cheeseand crackers” describes “a picnic basket having cheese, wherein thepicnic basket further has crackers”, as well as describes “a picnicbasket having crackers, wherein the picnic basket further has cheese”;the picnic basket further may contain one or more other items besidecheese and crackers.

The phrase “at least one” followed by a list of items joined by “and”denotes an item of the list but does not require every item of the list.Thus, “at least one of an apple and an orange” encompasses the followingmutually exclusive scenarios: there is an apple but no orange; there isan orange but no apple; and there is both an apple and an orange. Inthese scenarios if there is an apple, there may be more than one apple,and if there is an orange, there may be more than one orange. Moreover,the phrase “one or more” followed by a list of items joined by “and” isthe equivalent of “at least one” followed by the list of items joined by“and”.

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to theOrdinary Artisan that various modifications and variations can be madein the invention without departing from the scope or spirit of theinvention. For instance, features illustrated or described as part ofone embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the invention covers suchmodifications and variations as come within the scope of the appendedclaims and their equivalents.

A multi-panel skirt system as seen in the drawings includes a pluralityof skirt panels configured to be installed along a bottom side or wallof a cargo enclosure to reduce the amount of drag on the enclosure as itis being hauled or transported. Specifically, in several embodiments,the multi-panel skirt system preferably includes both a forward skirtpanel and an aft skirt panel installed underneath the cargo enclosure oneach of its opposed lateral sides. Each panel extends lengthwise betweena leading edge and a trailing edge and defines an aerodynamic shapebetween its leading and trailing edges. For instance, in severalembodiments, each panel preferably defines a compound or complexcurvature or shape between its leading and trailing edges so as tooptimize the aerodynamic performance and drag-reducing properties of thepanel. Specifically, in one embodiment, the trailing edge of each panelpreferably is positioned at or adjacent to its corresponding lateralside edge of the cargo enclosure, with the panel being curved or angledinwardly as it extends forward towards its leading edge such that theleading edge is spaced inwardly from the adjacent lateral side. In suchan embodiment, in addition to providing the ability to block wind fromflowing underneath the cargo enclosure along the lengths of the panels,each panel preferably is adapted to create a volume of low energy airunderneath the cargo enclosure to reduce the overall amount of drag onthe rear wheels. For example, the panel shapes preferably enable thepanels positioned along the upwind side of the enclosure (as defined bythe direction of the wind) to create a vortex at the leading edges ofsuch panels, which produces a lower pressure area underneath the cargoenclosure and also reduces the amount of drag on the panel itself. Inaddition, the shape of the panels preferably also allows the panelspositioned along the downwind side of the enclosure (as defined by thedirection of the wind) to capture the flow of air underneath the cargoenclosure along the inner surfaces of such panels and divert suchairflow outwardly from underneath the enclosure and away from the rearwheels.

Additionally, in combination with the shape of each panel, the relativepositioning of the forward and aft skirt panels along each lateral sideof the cargo enclosure preferably is selected to allow the air flowingalong the inner sides of the downwind panels to be expelled fromunderneath the cargo enclosure. For example, the forward and aft panelsinstalled relative to each lateral side of the cargo enclosurepreferably is mounted relative to each other such that a gap or air ventis defined between the trailing edge of the forward panel and theleading edge of the aft panel. In such an embodiment, due to thecurvature of the panels, the leading edge of the aft panel will bepositioned further inboard from the adjacent lateral side of the cargoenclosure than the trailing edge of the forward panel. As a result, whenan airflow is guided along the inner surface of the downwind forwardpanel, the airflow preferably is expelled from underneath the cargoenclosure via the air vent defined between the adjacent panels.

Referring now to FIGS. 1-4, several views of an example of a cargoenclosure 100 onto which one embodiment of a multi-panel skirt system200 has been installed is illustrated in accordance with a preferredembodiment of one or more aspects and features of the invention.Specifically, FIGS. 1 and 2 illustrate side and bottom views,respectively, of the cargo enclosure 100 coupled to a tractor 102 inaccordance with a preferred embodiment of one or more aspects andfeatures of the invention. Additionally, FIGS. 3 and 4 illustraterespective front and rear, bottom perspective views of the cargoenclosure 100 shown in FIGS. 1 and 2.

In several embodiments, the cargo enclosure 100 preferably generallydefines an enclosed space or volume for storing cargo. For example, asshown in FIGS. 1-4, the cargo enclosure 100 may, in one embodiment,define a rectangular storage or cargo space bounded along its sides by afront wall 104, a rear wall 106 and a plurality of additional enclosurewalls 108, 110, 112, 114 extending between the front and rear walls 104,106 in a lengthwise direction 115 of the cargo enclosure 100. Forinstance, in one embodiment, the cargo enclosure can include opposedside walls (e.g., a first side wall 108 and a second side wall 110), atop wall 112, and a bottom wall 114 extending between the front and rearwalls 104, 106 in the lengthwise direction 115. As is generallyunderstood, the top wall 112 can define the top or roof of the enclosedspace and the bottom wall 114 can define the bottom or floor of theenclosed space. Similarly, the side walls 108, 110 can generally definethe opposed lateral sides of the enclosed space. It should beappreciated that, in other embodiments, the various enclosure walls 104,106, 108, 110, 112, 114 of the cargo enclosure 100 can be configured inany other manner such that the enclosure 100 defines a storage spacehaving any other suitable shape.

As particularly shown in FIGS. 2-4, the cargo enclosure 100 can definelateral side edges 116, 118 extending in the lengthwise direction 115 ofthe enclosure 100 at the intersections between the bottom wall 114 andthe opposed side walls 108, 110. Specifically, the cargo enclosure 100can define a first lateral side edge 116 at the intersection between thebottom wall 114 and the first side wall 108, and a second lateral sideedge 118 at the intersection between the bottom wall 114 and the secondside wall 110. Each lateral side edge 116, 118 can generally extend inthe lengthwise direction 115 between the front and rear walls 104, 106of the cargo enclosure 100.

As particularly shown in FIG. 2, the opposed side walls 108, 110 of thecargo enclosure 100 (and, thus, the corresponding lateral side edges116, 118) are spaced apart from a lengthwise centerline 120 of the cargoenclosure 100 in a lateral direction 122 of the enclosure 100. In thisregard, for purposes of the disclosure provided herein and withoutintent to limit, the terms “laterally inboard” or simply “inboard” and“laterally outboard” or simply “outboard” will be used to describe thepositioning or orientation of components or features relative to thelengthwise centerline 120 or the opposed side walls/edges 108, 110, 116,118 of the cargo enclosure 100. Specifically, a feature(s) that islocated closer to the lengthwise centerline 120 than the opposed sidewall/edges 108, 110, 116, 118 in the lateral direction 122 shall beconsidered to be positioned inboard of a feature(s) that is locatedcloser to the opposed side wall/edges 108, 110, 116, 118 than thelengthwise centerline 120 in the lateral direction 120. Similarly, afeature(s) that is located closer to the opposed side wall/edges 108,110, 116, 118 than the lengthwise centerline 120 in the lateraldirection 122 shall be considered to be positioned outboard of afeature(s) that is located closer to the lengthwise centerline 120 thanthe opposed side wall/edges 108, 110, 116, 118 in the lateral direction122.

It should be appreciated that the cargo enclosure 100 can generallydefine any suitable dimensions. For example, as shown in FIG. 1, thecargo enclosure 100 can define a height 124 in a heightwise direction126 of the cargo enclosure 100 between the top wall 112 and the bottomwall 114 of the enclosure 100. In addition, as shown in FIG. 2, thecargo enclosure 100 can define a lateral width 128 in the lateraldirection 122 of the cargo enclosure 100 between the opposed side walls108, 110 of the enclosure 100 and a length 130 in the lengthwisedirection 115 between the front wall 104 and the rear wall 106 of theenclosure 100.

Moreover, as shown in FIGS. 1-4, the cargo enclosure 100 may, in severalembodiments, form part of a trailer configured for use as atractor-trailer combination. In such embodiments, the cargo enclosure100 can include or be associated with any suitable trailer-relatedcomponents, such as landing gear 132, a rear wheel assembly 134, or thelike. As shown, the rear wheel assembly 134 can include, for example,rear wheels 136, axles 138, and a suspension system 140. Additionally,when used in a tractor-trailer combination, the cargo enclosure 100 canbe configured to be coupled to or hauled by a tractor 102 having anysuitable tractor configuration. For example, as shown in the illustratedembodiment, the tractor 102 can include a cab 142 supported on a chassis144 and a fifth wheel coupling 146 extending behind the cab 142 forcoupling the tractor 102 to the cargo enclosure 100. Additionally, asparticularly shown in FIG. 1, the tractor 102 can include an air dam 148mounted on top of the cab 142.

It should be appreciated that, in other embodiments, the cargo enclosure100 can correspond to or form part of any other suitable transportvehicle or transport or storage system. For example, the cargo enclosure100 can correspond to or form part of the rear storage enclosure of astraight or box truck. In another embodiment, the cargo enclosure 100can correspond to or form part of a railway car or boxcar, a motorhome,bus, cab-over-type vehicle or any other suitable movable storagecompartment or space, regardless of whether the compartment or space ispulled, pushed or self-propelled.

As indicated above, in accordance with a preferred embodiment of one ormore aspects and features of the invention, a multi-panel skirt system200 can be installed along the bottom wall 114 of the cargo enclosure100 relative to the opposed lateral side edges 116, 118 of the enclosure100. Specifically, in several embodiments, the multi-panel skirt system200 can include a pair of forward skirt panels and a pair of aft skirtpanels installed between the landing gear 132 and the rear wheelassembly 134 of the cargo enclosure 100, with the forward skirt panelsbeing installed underneath the cargo enclosure 100 forward of the aftskirt panels in the lengthwise direction 115 relative to the forwarddirection of travel for the enclosure 100 (e.g., as indicated by arrow150 in FIGS. 1 and 2). For example, as shown, first forward and aftskirt panels 202A, 204A are installed along the bottom wall 114 of thecargo enclosure 100 on a first lateral side. Similarly, second forwardand aft skirt panels 202B, 204B are installed along the bottom wall 114of the cargo enclosure 100 on the opposite lateral side.

The disclosed skirt panels can generally be configured to substantiallyblock air from flowing underneath the enclosure 100, thereby creating apocket of low energy air along the undercarriage that reduces theoverall amount of drag on the cargo enclosure 100, particularly on therear wheel assembly 134. Additionally, each individual panel can beshaped or otherwise aerodynamically configured so as to produce a vortexat its leading edge that creates a low pressure area adjacent to thepanel, thereby reducing the resulting drag on the panel itself.Moreover, the relative positioning of the panels can allow for anyairflow that is actually directed underneath the enclosure 100 to beexpelled therefrom. For example, as shown in the illustrated embodiment,each forward skirt panel can be installed relative to its adjacent aftskirt panel along the bottom wall 114 of the cargo enclosure 100 suchthat a gap or air vent 206 is defined between each respective pair offorward and aft panels. As a result, an airflow captured underneath thecargo enclosure 100 by the forward skirt panel positioned along thedownwind side of the enclosure 100 can be expelled through the air vent206 defined between such forward panel and its respective aft skirtpanel as opposed to being directed downstream towards the rear wheelassembly 134.

In addition to providing a channel for expelling air from underneath thecargo enclosure 100, the air vents or gaps 206 defined between theforward and aft panels can also provide areas of increased verticalclearance underneath the enclosure 100 relative to the adjacent travelsurface. Thus, as compared to conventional skirt designs that extendcontinuously between the landing gear 132 and the rear wheels 136, theskirt panels of the disclosed system 200 can have a reduced likelihoodof contact with the adjacent travel surface or other impediments. Inaddition, the air vents or gaps 206 can also provide a convenientpathway for accessing the undercarriage of the cargo enclosure 100(e.g., for service personnel or for the driver).

It should also be appreciated that the various skirt panels disclosedherein can generally be configured to be supported relative to thebottom wall 114 of the cargo enclosure 100 using any suitable bracketassembly or other mounting configuration. For example, as schematicallyshown in FIG. 2, one or more rigid or resilient mounting brackets 208can be coupled between the bottom wall 114 and each panel to mount thepanel to the cargo enclosure 100. In such an embodiment, the specificconfiguration of the mounting brackets 208 can generally very dependingon the desired mounting configuration. However, the Ordinary Artisanwill appreciate that various different bracket arrangements arecommercially available that can be used in mounting the disclosed skirtpanels to the underside of a cargo enclosure.

Referring now to FIGS. 5 and 6, differing views of one of the forwardskirt panels described above are illustrated in accordance with apreferred embodiment of one or more aspects and features of theinvention. Specifically, FIGS. 5 and 6 illustrate respective side andbottom views of the first forward skirt panel 202A shown in FIGS. 1-4,with FIG. 6 depicting first and second dashed reference lines toindicate the locations of the lengthwise centerline 120 and the adjacentside wall/edge 108, 116 of the cargo enclosure 100 relative to theforward skirt panel 202A when the panel 202A is in its installed state.It should be appreciated that the second forward panel 202B can beconfigured to mirror the first forward panel 202A and can have the samerelative positioning to its adjacent side wall/edge 110, 118 of thecargo enclosure 100 as that shown in FIG. 6.

As shown, the forward skirt panel 202A can generally be configured toextend in the lengthwise direction 115 between a leading edge 220 and atrailing edge 222, and in the heightwise direction 126 between a top end224 and a bottom end 226. The forward skirt panel 202A can also define alaterally outer side or surface 228 and a laterally inner side orsurface 230, with the outer surface 228 generally facing outboard in thelateral direction 122 (i.e., in a direction away from the underside ofthe enclosure 100) and the inner surface 230 generally facing inboard inthe lateral direction 122 (i.e., towards the opposed side of theenclosure 100). As shown in FIG. 5, the forward skirt panel 202A candefine a panel height 232 between its top and bottom ends 224, 226 inthe heightwise direction 126 and a panel length 234 between its leadingand trailing edges 220, 222 in the lengthwise direction 115. Inaddition, as shown in FIG. 6, the panel 202A defines a lateral depth 236between its leading and trailing edges 220, 222 in the lateral direction122.

The top end 224 of the forward skirt panel 202A can generally beconfigured to be positioned directly adjacent to the bottom wall 114 ofthe enclosure 100 when the panel 202A is installed thereon. In such anembodiment, the top end 224 of the forward skirt panel 202A may, forexample, be configured to define a planar or straight profile such thatthe top end 224 can be seated flush or substantially flush against thebottom wall 114 of the enclosure 100. In contrast, the bottom end 226 ofthe forward skirt panel 202A can be configured to be spaced apart fromthe bottom wall 114 of the cargo enclosure 100 and can generallycorrespond to the edge or end of forward skirt panel 202A configured tobe positioned closest to the travel surface across which the enclosure100 is being traversed or towed. As will be described below, given itsproximity to the travel surface for the cargo enclosure 100, a portionof the forward skirt panel 202A adjacent to its bottom end 226 can beformed from a different material than the remainder of the panel 202A(e.g., a more resilient or flexible material) to prevent damage to thepanel 202A caused by contact with the travel surface or otherimpediments positioned relative to the travel surface (e.g., speedbumps, etc.).

Additionally, in several embodiments, the forward skirt panel 202A canbe configured to define a profile or shape that projects laterallyinwardly or inboard (i.e., away from the adjacent side wall/edge 108,116 and towards the lengthwise centerline 120 of the enclosure 100) asthe panel 202A extends in the lengthwise direction 115 from its trailingedge 222 to its leading edge 220. Specifically, as shown in FIG. 6, wheninstalled relative to the adjacent side wall/edge 108, 116 of the cargoenclosure 100 (e.g., as indicated by reference line 108, 116 in FIG. 6),the trailing edge 222 of the panel 202A is configured to be aligned withor positioned immediately inboard of the adjacent side wall/edge 108,116. However, as the panel 202A extends in the lengthwise direction 115towards its leading edge 220, the panel 202A curves or extends laterallyinboard such that the leading edge 220 of the panel 202A is positionedfurther inboard (i.e., closer to the lengthwise centerline 120) than thetrailing edge 222. For example, as shown in FIG. 6, in one embodiment,the panel 202A can be curved or angled inwardly such that the leadingedge 220 of the panel 202A is positioned closer to the lengthwisecenterline 120 in the lateral direction 122 than the adjacent sidewall/edge 108, 116 of the enclosure 100 (i.e., a lateral distance 238defined between the leading edge 220 and the lengthwise centerline 120is less than a lateral distance 240 defined between the leading edge 220and the adjacent side wall/edge 108, 116).

Moreover, in several embodiments, the panel 202A can define a complex orcompound shape or profile in the lateral direction 122 such that therate at which the lateral depth 236 of the panel 202A changes as itextends in the lengthwise direction 115 from its trailing edge 222 toits leading edge 224 varies along at least a portion of the length 234of the panel 202A. For example, in the illustrated embodiment, theforward skirt panel 202A has a complex or compound lateral shape orprofile defined across first and second lengthwise sections 242, 244 ofthe panel 202A, with the first lengthwise section 242 extending in thelengthwise direction 115 between the trailing edge 222 and a transitionpoint 246 defined between the first and second lengthwise sections 242,244, and the second lengthwise section 244 extending in the lengthwisedirection 115 between the transition point 246 and the leading edge 220.As shown in FIG. 6, the first lengthwise section 242 defines a lateralprofile that differs from the lateral profile of the second lengthwisesection 244 such that the rate at which the lateral depth 236 of thepanel 202A changes as it extends from the trailing edge 222 to thetransition point 246 is relatively small compared to the rate at whichthe lateral depth 236 changes as the panel 202A further extends from thetransition point 246 out to its leading edge 220. Specifically, thefirst lengthwise section 242 defines a slightly curved or arcuatelateral profile having a relatively large radius of curvature such thatthe panel 202A gradually transitions inboard towards the lengthwisecenterline 120 (and away from the adjacent side wall/edge 108, 116) asit extends from the trailing edge 222 towards the transition point 246.In contrast, the second lengthwise section 244 defines a more linear orstraight lateral profile having a shaper inboard angle such that thepanel 202A transitions inboard towards the lengthwise centerline 120(and away from the adjacent side wall/edge 108, 116) at a greater rateas it extends from the transition point 246 towards the leading edge220. The sharper inboard lateral profile defined by the secondlengthwise section 244 can facilitate the generation of a vortex or lowpressure area adjacent to the leading edge 220 as an airflow is directedaround or across such portion of the panel 202A while the more gradualoutboard lateral profile defined by the first lengthwise section 242 canbe configured to guide an airflow directed along the outer surface 228of the panel 202A laterally outboard as it flows towards the trailingedge 222 of the panel 202A.

In several embodiments, the panel 202A can define a tapered or varyingheightwise profile along the leading edge 220 of the panel 202A as itextends between the top and bottom ends 224, 226 of the panel 202A. Forexample, in the illustrated embodiment, the location at which theleading edge 220 intersects the top end 224 of the panel 202A is forwardof the location at which the leading edge 220 intersects the bottom end226 of the panel 200 relative to the forward travel direction 150 of theenclosure 100. As a result, the overall height 232 of the panel 202Adefined in the heightwise direction 126 can generally decrease at theleading edge 220 as it extends upwardly towards the top end 224 of thepanel 202A. In one embodiment, such tapering of the height 232 of thepanel 202A at the leading edge 220 can be constant or linear between thetop and bottom ends 224, 226. Alternatively, the degree or rate at whichthe height 232 tapers along the leading edge 220 can vary between thetop and bottom ends 224, 226. For instance, as shown in the embodimentof FIG. 5, the rate at which the height 232 tapers along the leadingedge 220 is different along a lower portion of the leading edge 220 ascompared to an upper portion of the leading edge 200.

Additionally, in several embodiments, the trailing edge 222 of the panel202A can define a contoured shape as it extends between the top andbottom ends 224, 226 of the panel 202A. For example, as shown in FIG. 5,the trailing edge 222 has a generally curved or arcuate profile.However, in other embodiments, the trailing edge 222 can define anyother suitable shape or profile, such as by extending generallyperpendicular between the top and bottom ends 224, 226 of the panel 202Aor by configuring the panel 202A to define tapered or varying heightwiseprofile along the trailing edge 222.

It should be appreciated that, in general, the forward skirt panel 202Acan be formed from any suitable material that allows it to function asdescribed herein. For instance, in several embodiments, the forwardskirt panel 202A can be formed from a rigid or semi-rigid polymermaterial. Additionally, in one embodiment, the forward skirt panel 202Acan be formed entirely from a single, uniform material as a single pieceor multiple pieces connected or otherwise secured together. For example,the forward skirt panel can be formed from a plurality of subpanelsconnected together. Alternatively, one or more portions of the panel202A can be formed from differing materials. For example, as indicatedabove, a portion of the panel 202A adjacent to the bottom end 226 (e.g.,the heightwise section indicated at 248) can be formed from a differentmaterial than the remainder of the panel 202A, such as by forming suchlower portion 248 with a more flexible or resilient material than thematerial used to form the remainder of the panel 202A.

Referring now to FIGS. 7 and 8, differing views of one of the aft skirtpanels described above is illustrated in accordance with a preferredembodiment of one or more aspects and features of the invention.Specifically, FIGS. 7 and 8 illustrate respective side and bottom viewsof the first aft skirt panel 204A shown in FIGS. 1-4, with FIG. 8depicting first and second dashed reference lines to indicate thelocations of the lengthwise centerline 120 and the adjacent sidewall/edge 108, 116 of the cargo enclosure 100 relative to the aft skirtpanel 204A when the panel 204A is in its installed state. It should beappreciated that the second aft panel 204B can be configured to mirrorthe first aft panel 204A and can have the same relative positioning toits adjacent side wall/edge 110, 118 of the cargo enclosure 100 as thatshown in FIG. 8.

As shown, the aft skirt panel 204A can generally be configured to extendin the lengthwise direction 115 between a leading edge 250 and atrailing edge 252, and in the heightwise direction 126 between a top end254 and a bottom end 256. The aft skirt panel can also define alaterally outer side or surface 258 and a laterally inner side orsurface 260, with the outer surface 258 generally facing outboard in thelateral direction 122 (i.e., in a direction away from the underside ofthe enclosure 100) and the inner surface 260 generally facing inboard inthe lateral direction 122 (i.e., towards the opposed side of theenclosure 100). As shown in FIG. 7, the aft skirt panel 204A can definea panel height 262 between its top and bottom ends 254, 256 in theheightwise direction 126 and a panel length 264 between its leading andtrailing edges 250, 252 in the lengthwise direction 115. In addition, asshown in FIG. 8, the panel 204A defines a lateral depth 266 between itsleading and trailing edges 250, 252 in the lateral direction 122.

The top end 254 of the aft skirt panel 204A can generally be configuredto be positioned directly adjacent to the bottom wall 114 of theenclosure 100 when the panel 204A is installed thereon. In such anembodiment, the top end 254 of the aft skirt panel 204A may, forexample, be configured to define a planar or straight profile such thatthe top end 254 can be seated flush or substantially flush against thebottom wall 114 of the enclosure 100. In contrast, the bottom end 256 ofthe aft skirt panel 204A can be configured to be spaced apart from thebottom wall 114 of the cargo enclosure 100 and can generally correspondto the edge or end of aft skirt panel 204A configured to be positionedclosest to the travel surface across which the enclosure 100 is beingtraversed or towed. As will be described below, given its proximity tothe travel surface for the cargo enclosure 100, a portion of the aftskirt panel 204A adjacent to its bottom end 256 can be formed from adifferent material than the remainder of the panel 204A (e.g., a moreresilient or flexible material) to prevent damage to the panel 204Acaused by contact with the travel surface or other impedimentspositioned relative to the travel surface (e.g., speed bumps, etc.).

Additionally, in several embodiments, the aft skirt panel 204A can beconfigured to define a profile or shape that projects laterally inwardlyor inboard (i.e., away from the adjacent side wall/edge 108, 116 andtowards the lengthwise centerline 120 of the enclosure 100) as the panel204A extends in the lengthwise direction 115 from its trailing edge 252to its leading edge 250. Specifically, as shown in FIG. 8, wheninstalled relative to the adjacent side wall/edge 108, 116 of the cargoenclosure 100 (e.g., as indicated by reference line 108, 116 in FIG. 8),the trailing edge 252 of the panel 204A is configured to be positionedat or immediately inboard of the adjacent side wall/edge 108, 116.However, as the panel 204A extends in the lengthwise direction 115towards its leading edge 250, the panel 204A curves or extends laterallyinboard such that the leading edge 250 of the panel 204A is positionedfurther inboard (i.e., closer to the lengthwise centerline 120) than thetrailing edge 252.

Moreover, in several embodiments, the aft skirt panel can define acomplex or compound shape or profile in the lateral direction 122 suchthat the rate at which the lateral depth 266 of the panel changes as itextends in the lengthwise direction 115 from its trailing edge 252 toits leading edge 250 varies along at least a portion of the length 264of the panel 204A. For example, in the illustrated embodiment, the aftskirt panel 204A has complex or compound lateral shape or profiledefined across first, second, and third lengthwise sections 268, 270,272 of the panel 204A, with the first lengthwise section 268 extendingin the lengthwise direction 115 between the trailing edge 250 and afirst transition point 274 defined between the first and secondlengthwise sections 268, 270, the second lengthwise section 270extending in the lengthwise direction 115 between the first transitionpoint 274 and a second transition point 276 defined between the secondand third lengthwise sections 270, 272, and the third lengthwise section272 extending in the lengthwise direction 115 between the secondtransition point 276 and the leading edge 250 of the panel 204A. Asshown in FIG. 8, the first lengthwise section 268 generally defines aflat or planar lateral profile across which the panel 204A extendsgenerally parallel to the adjacent side wall/edge 108, 116 of the cargoenclosure 100 while the second and third lengthwise sections 270, 272define laterally inboard extending profiles. Additionally, as shown inthe illustrated embodiment, the second lengthwise section 270 defines alateral profile that differs from the lateral profile of the thirdlengthwise section 272 such that the rate at which the lateral depth 266of the panel 204A changes as it extends from the first transition point274 to the second transition point 276 is relatively small compared tothe rate at which the lateral depth 266 changes as the panel 204Afurther extends from the second transition point 276 out to the leadingedge 250. Specifically, the second lengthwise section 270 defines aslightly curved or arcuate lateral profile having a relatively largeradius of curvature such that the panel 204A gradually transitionsinboard towards the lengthwise centerline 120 (and away from theadjacent side wall/edge 108, 116) as it extends from the firsttransition point 274 towards the second transition point 276. Incontrast, the third lengthwise section 272 defines a more pronouncedcurved or arcuate lateral profile having a relatively smaller radius ofcurvature such that the panel 204A transitions inboard towards thelengthwise centerline 120 (and away from the adjacent side wall/edge108, 116) at a greater rate as it extends from the second transitionpoint 276 towards the leading edge 250 of the panel 204A. The sharperinboard lateral profile defined by the third lengthwise section 272 canfacilitate the generation of a vortex or low pressure area adjacent tothe leading edge 250 as an airflow is directed around or across suchportion of the panel 204A while the more gradual outboard lateralprofile defined by the second lengthwise section 270 can be configuredto guide an airflow directed along the outer surface 258 of the panel204A laterally outboard as it flows towards the trailing edge 252 of thepanel 204A.

In several embodiments, the panel 204A can define a tapered or varyingheightwise profile along the leading edge 250 of the panel 204A as itextends between the top and bottom ends 254, 256 of the panel 204A. Forexample, in the illustrated embodiment, the location at which theleading edge 250 intersects the top end 254 of the panel 204A is forwardof the location at which the leading edge 250 intersects the bottom end256 of the panel relative to the forward travel direction 150 of theenclosure 100. As a result, the overall height 262 of the panel 204Adefined in the heightwise direction 126 can generally decrease at theleading edge 260 as it extends upwardly towards the top end 254 of thepanel 204A. In one embodiment, such tapering of the height 262 of thepanel 204A at the leading edge 250 can be constant or linear between thetop and bottom ends 254, 256. Alternatively, as shown in FIG. 7, thedegree or rate at which the height 262 tapers along the leading edge 250can vary between the top and bottom ends 254, 256.

Additionally, in several embodiments, the trailing edge 252 of the panel204A can define a contoured shape as it extends between the top andbottom ends 254, 256 of the panel 204A. For example, as shown in FIG. 7,the trailing edge 252 has a generally curved or arcuate profile. In suchan embodiment, the curved heightwise profile of the trailing edge 252may, for instance, be selected so as to provide clearance between thetrailing edge 252 of the panel 204A and the wheels 136 of the rear wheelassembly 134. However, in other embodiments, the trailing edge 252 candefine any other suitable shape or profile, such as by extendinggenerally perpendicular between the top and bottom ends 254, 256 of thepanel 204A or by configuring the panel 204A to define a tapered orvarying heightwise profile along the trailing edge 252.

It should be appreciated that, in general, the aft skirt panel 204A cangenerally be formed from any suitable material that allows it tofunction as described herein. For instance, in several embodiments, theaft skirt panel 204A can be formed from a rigid or semi-rigid polymermaterial. Additionally, in one embodiment, the aft skirt panel 204A canbe formed entirely from a single, uniform material as a single piece ormultiple pieces connected or otherwise secured together. For example,the aft skirt panel can be formed from a plurality of subpanelsconnected together. Alternatively, one or more portions of the panel204A can be formed from differing materials. For example, as indicatedabove, a portion of the panel 204A adjacent to the bottom end 256 (e.g.,the heightwise section indicated at 278) can be formed from adifferential material than the remainder of the panel 204A, such as byforming such lower portion 278 with a more flexible or resilientmaterial than the material used to form the remainder of the panel 204A.

Referring now to FIG. 9, close-up, bottom view of a portion of the cargoenclosure 100 shown in FIGS. 1-4 is illustrated in accordance with apreferred embodiment of one or more aspects and features of theinvention. Specifically, FIG. 9 illustrates a lengthwise portion of thecargo enclosure 100 extending between the landing gear 132 and the rearwheel assembly 134 of the enclosure 100, particularly illustrating theabove-described skirt panels installed along the bottom wall 114 of theenclosure 100 between its landing gear 132 and rear wheel assembly 134.

As shown in FIG. 9, the forward skirt panels are configured to beinstalled along the bottom wall 114 of the cargo enclosure 100 in frontor forward of the aft skirt panels relative to the forward traveldirection 150 of the enclosure 100. For example, the forward skirtpanels can be configured to be installed along the bottom wall 114 suchthat the leading edges 220 of the forward skirt panels are positioned ator adjacent to the landing gear 132 of the cargo enclosure 100 while theaft skirt panels can be configured to be installed along the bottom wall114 such that the trailing edges 252 of the aft skirt panels arepositioned at or generally adjacent to the rear wheels 136 of the rearwheel assembly 134 of the cargo enclosure 100. Additionally, as shown inFIG. 9, in one embodiment, the forward and aft skirt panels can bespaced apart from one another in the lengthwise direction 115 such thata lengthwise gap 282 is defined between the trailing edge 222 of eachforward skirt panel and the leading edge 250 of each adjacent aft skirtpanel 204. As indicated above, such lengthwise gap 282 can form an airvent 206 between the adjacent skirt panels . Alternatively, as will bedescribed below with reference to FIGS. 11 and 12, the forward and aftskirt panels can be configured to overlap each other in the lengthwisedirection 115 while still defining an air vent therebetween.

Additionally, in several embodiments, the laterally inboard extendingprofiles of the forward skirt panels can be selected such that a portionof each forward panel overlaps an adjacent portion of the landing gear132 of the cargo enclosure 100 in the lengthwise direction 115. Forexample, as shown in

FIG. 9, the landing gear 132 extends in the lengthwise direction 115between a forward end 152 and an aft end 154 and includes a cross-wisestructural member 156 extending laterally between opposed first andsecond lateral sides 158, 160 of the landing gear 132. Additionally, alateral distance 162 is defined between each lateral side 158, 160 ofthe landing gear 132 and the adjacent lateral side edge 116, 118 of thecargo enclosure 100. As shown in the illustrated embodiment, the firstlengthwise section 242 of each forward skirt panel curves inwardly orinboard from the trailing edge 222 of each panel such that thetransition point 246 defined between the first and second lengthwisesections 242, 244 of each panel is generally positioned at or adjacentto the aft end 154 of the landing gear 132 along each of its lateralsides 158, 160. In such an embodiment, the change in the lateral depth236 of each forward skirt panel across its first lengthwise section 242is generally equal to the lateral distance 162 defined between eachlateral side 158, 160 of the landing gear 132 and the adjacent lateralside edges 116, 118 of the cargo enclosure 100.

Moreover, as shown in FIG. 9, the second lengthwise section 244 of eachforward skirt panel extends from the transition point 246 forward of theaft end 154 of the landing gear 132 such that at least a portion of thesecond lengthwise section 244 of each forward skirt panel is positioneddirectly between the opposed lateral sides 158, 160 of the landing gear132 and overlaps portions thereof in the lengthwise direction 115. Forexample, in the illustrated embodiment, each forward skirt panel extendsforward past the aft end 154 of the landing gear 132 such that theleading edge 220 of each panel is positioned generally adjacent to thecross-wise structural member 156 of the landing gear 132. Furthermore,the sharp inboard angles of the second lengthwise sections 244 of theforward skirt panels creates a converging lateral gap 280 directlybetween the skirt panels as the skirt panels extend in the forwardtravel direction 150 towards their respective leading edges 220. Such anarrowed lateral gap 280 between the forward skirt panels can serve toreduce the amount of cross-flow that can be directed between the panelsfrom the front side of the enclosure 100. Additionally, the narrowedlateral gap 280 can facilitate guiding any airflow that is directedbetween the skirt panels in a manner that reduces the overall drag onthe cargo enclosure 100 or that allows for such airflow to be expelledfrom underneath the enclosure 100.

Referring still to FIG. 9, due to the laterally inboard extendingprofiles of the aft skirt panels 204, the leading edge 250 of each aftskirt panel is positioned inboard of the trailing edge 222 of itsadjacent forward skirt panel 202. As will be described below, suchrelative lateral positioning of the forward and aft skirt panels 202, 24can facilitate expelling an airflow directed between the forward skirtpanels from underneath the cargo enclosure 100. For example, theinwardly curved profile defined by the second and third lengthwisesections 270, 272 of the aft skirt panels can assist in guiding suchairflow outboard along the aft skirt panels towards the lateral sideedges 116, 118 of the cargo enclosure 100 (and, thus, away from the rearwheel assembly 134).

Referring now to FIG. 10, another bottom view of the lengthwise sectionof the cargo enclosure 100 shown in FIG. 9 is illustrated in accordancewith a preferred embodiment of one or more aspects and features of theinvention, particularly illustrating an example of a cross-flow (asindicated by the arrows 284) relative to the skirt panels when the cargoenclosure 100 is subject to a cross-flow. Specifically, in theillustrated embodiment, the cross-flow 284 is directed across the cargoenclosure 100 in the lateral direction 122 from its first side wall/edge108, 116 towards its second side wall/edge 110, 118. As a result, forthe purposes of describing FIG. 10, the first forward and aft skirtpanels 202A, 204A will also be referred to as the upwind forward and aftpanels while the second forward and aft skirt panels 202B, 204B willalso be referred to as the downwind forward and aft panels. It should beappreciated that, as used herein, the term cross-flow is generally usedto refer to an airflow that is directed across the cargo enclosure 100at a non-zero angle relative to the lengthwise direction 115 of theenclosure 100, such as an angle ranging from 0.5 degrees relative to thelengthwise direction 115 to 20 degrees relative to the lengthwisedirection.

As shown in FIG. 10, when a cross-flow 284 is directed towards the cargoenclosure 10, the upwind skirt panels 202A, 204A can be configured toblock a significant portion of the airflow 284 from flowing underneaththe cargo enclosure 100. Specifically, as the cross-flow 284 contactsthe outer surface 228, 258 of each upwind skirt panel 202A, 204A, thecontour of each upwind skirt panel 202A, 204A can be configured to guidethe flow outboard along the outer surface 228, 258 of the panel 202A,204A towards its respective trailing edge 222, 252. As a result, suchportion of the cross-flow 284 can be prevented from being directedunderneath the cargo enclosure 100.

Additionally, as shown in FIG. 10, when the area around the landing gear132 of the cargo enclosure 100 experiences or is subject to a cross-flow284, a portion of the cross-flow 284 can be sucked into or can otherwiseflow underneath the enclosure 100 and can be subsequently divertedthrough the lateral gap 280 defined between the forward skirt panels202A, 202B. In such instance, as the cross-flow 284 is directed past(i.e., around, across, or adjacent to) the leading edge 220 of theupwind forward panel 202A, a vortex 286 can be generated immediatelydownstream of the leading edge 220 of the upwind forward panel 202A thatcreates a low pressure area adjacent to the inner surface 230 of suchpanel 202A, thereby reducing the overall amount of drag on the panel202A. Specifically, the inwardly curled or angled shape of the secondlengthwise section 244 of the upwind forward skirt panel 202A can beadapted to create a spiraling flow as the airflow 284 wraps around theleading edge 220 of the upwind forward panel 202A, thereby increasingthe wake downstream of the leading edge 220.

Moreover, as shown in FIG. 10, the profile of the downwind forward panel202B is configured such that any portion of the cross-flow 284 directedbetween the forward panels that is not sucked into the vortex 286generated by the upwind forward panel 202A will be captured along theinner surface 230 of the downwind forward panel 202B and guided alongsuch panel 202B towards is trailing edge 222. Specifically, in theillustrated embodiment, given the inwardly projecting profile of thesecond lengthwise section 244 of the downwind forward skirt panel 202B,a portion of the cross-flow 284 directed between the forward panels willstick to the inner surface 230 of the downwind forward skirt panel 202Bat or adjacent to its leading edge 220 and will subsequently flow alongthe inner surface 230 to the trailing edge 222 of the panel 202B. Atsuch point, the airflow along the inner surface 230 of the downwindforward skirt panel 202B will be expelled from underneath the cargoenclosure 100 via the air vent 206 defined between the downwind forwardand aft skirt panels 202B, 204B. This evacuation of the airflow betweenthe downwind skirt panels 202B, 204B is made possible due, at least inpart, to the relative lateral positioning of such panels 202B, 204B.Specifically, as indicated above, the leading edge 250 of the downwindaft panel 204B is positioned inboard of the trailing edge 222 of thedownwind forward panel 202B. Thus, as the captured airflow 284 isdirected along the inner surface 230 of the downwind forward panel 202Band flows past the trailing edge 222 of such panel 202B, the airflow 284is subsequently captured by the outer surface 258 of the downwind aftpanel 204B and flows outboard along the outer surface 258 of suchdownstream panel 204B.

It should also be appreciated that, to the extent any portion of thecross-flow 284 is directed from the outside through the air vent 206defined between the upwind skirt panels 202A, 204A, the aft skirt panelscan be configured to function similar to the forward skirt panels whensubject to such a cross-flow. For example, the camber or shape of thethird lengthwise section 272 of the upwind aft panel 204A can beconfigured to generate a vortex 288 when an airflow is directed past(i.e., around, across, or adjacent to) to the leading edge 250 of theupwind aft panel 204B, thereby creating an area of low pressureimmediately downstream of the leading edge 250. In addition, a portionof the cross-flow 284 flowing through the air vent 206 and across thebottom wall 114 of the cargo enclosure 100 will be captured along theinner surface 260 of the downwind aft panel 204B and guided along suchsurface 260 towards the trailing end 252 of the downwind aft panel 204B.At such point, the airflow flowing along the downwind aft panel 204B canbe expelled laterally outwardly through the gap defined between thetrailing edge 252 of the downwind aft panel 204B and the rear wheels 136of the rear wheel assembly 134.

Referring now to FIGS. 11 and 12, differing views of an alternativeembodiment of the disclosed multi-panel skirt system 200 are illustratedin accordance with a preferred embodiment of one or more aspects andfeatures of the invention. Specifically, FIG. 11 illustrates a similarbottom view of the cargo enclosure 100 as that shown in FIG. 9 with avariation of the skirt panels installed thereto. Additionally, FIG. 12illustrates a full side view of the cargo enclosure shown in FIG. 11,particularly illustrating the relative positioning of the alternativeembodiment of the skirt panels shown in FIG. 11.

As shown in FIG. 11, the skirt panels are generally configured similarlyto that described above with reference to FIGS. 1-10. However, in theillustrated embodiment, the relative lengths of the front skirt panelsor the aft skirt panels have been increased such that the forward skirtpanels overlap the aft skirt panels in the lengthwise direction 115 ofthe cargo enclosure 100. Specifically, as shown in FIG. 11, the forwardskirt panels are installed relative to the aft skirt panels such thatthe trailing edge 222 of each forward skirt panel is located aft orbehind the leading edge 250 of the adjacent aft skirt panel relative tothe forward travel direction 150 of the cargo enclosure 100. As aresult, the likelihood of a cross-flow being directed from the outsidethrough the air vent 206 defined between the adjacent panels issignificantly reduced or eliminated. Additionally, as shown in FIG. 11,similar to the embodiment described above, the leading edge 250 of eachaft skirt panel is located inboard of the trailing edge 222 of theadjacent forward skirt panel 204. As a result, a suitable gap is definedbetween each pair of adjacent skirt panels for forming the air vent 206,thereby allowing an airflow flowing along the inner surface of thedownwind forward skirt panel to be evacuated from underneath theenclosure 100.

Additionally, as shown in FIG. 12, the heightwise profile of thetrailing edge 222 of the forward skirt panels has been altered ascompared to the embodiment described above with reference to FIG. 5.Specifically, the forward skirt panel defines a tapered heightwiseprofile along the trailing edge 220 such that the height of the paneldecreases as the trailing edge 220 extends upwardly from the bottom endof the panel to the top end of the panel 202.

Based on the foregoing description, it will be readily understood by theOrdinary Artisan that the invention has broad utility and application.Many embodiments and adaptations of the invention other than thosespecifically described herein, as well as many variations,modifications, and equivalent arrangements, will be apparent from orreasonably suggested by the invention and the foregoing descriptionsthereof, without departing from the substance or scope of the invention.Accordingly, while the invention has been described herein in detail inrelation to one or more preferred embodiments, it is to be understoodthat this disclosure is only illustrative and exemplary of the inventionand is made merely for the purpose of providing a full and enablingdisclosure of the invention. The foregoing disclosure is not intended tobe construed to limit the invention or otherwise exclude any such otherembodiments, adaptations, variations, modifications or equivalentarrangements, the invention being limited only by the claims appendedhereto and the equivalents thereof.

What is claimed is:
 1. A cargo enclosure, comprising: (a) a top wall;(b) front and rear walls; (c) first and second side walls extendingbetween the front and rear walls in a lengthwise direction of the cargoenclosure; (d) a bottom wall extending between the front and rear wallsin the lengthwise direction and between the first and second side wallsin a lateral direction of the cargo enclosure, the first side wallintersecting the bottom wall at a first lateral side edge of the cargoenclosure, the second side wall intersecting the bottom wall at a secondlateral side edge of the cargo enclosure, wherein the top wall, thefront and rear walls, the side walls, and the bottom wall enclose acargo space of the cargo enclosure; and (e) a multi-panel skirt systeminstalled or otherwise secured to the bottom wall, the multi-panel skirtsystem: (i) a first forward skirt panel extending along the bottom wallgenerally in the lengthwise direction between a leading edge and atrailing edge, the trailing edge of the first forward skirt panel beinglocated adjacent to and aligned with or positioned laterally inboard ofthe first lateral side edge of the cargo enclosure; and (ii) a first aftskirt panel extending along the bottom wall generally in the lengthwisedirection between a leading edge and a trailing edge aft of the firstforward skirt panel relative to a forward travel direction of the cargoenclosure, the trailing edge of the first aft skirt panel being locatedadjacent to and aligned with or positioned laterally inboard of thefirst lateral side edge of the cargo enclosure; (iii) wherein the firstaft skirt panel extends laterally inboard as the first aft skirt panelextends in the lengthwise direction from its trailing edge to itsleading edge such that the leading edge of the first aft skirt panel ispositioned laterally inboard of the trailing edge of the first forwardskirt panel.
 2. The cargo enclosure of claim 1, wherein the leading edgeof the first forward skirt panel is positioned further laterally inboardthan the trailing edge of the first forward skirt panel.
 3. The cargoenclosure of claim 2, wherein the cargo enclosure defines a lengthwisecenterline extending in the lengthwise direction that is centeredrelative to the first and second lateral side edges in the lateraldirection, the leading edge of the first forward skirt panel beingpositioned a lateral distance from the lengthwise centerline that isless than a lateral distance defined between the leading edge of firstforward skirt panel and the first lateral side edge of the cargoenclosure.
 4. The cargo enclosure of claim 1, wherein the trailing edgeof the first forward skirt panel is positioned forward of the leadingedge of the first aft skirt panel relative to the forward traveldirection for the cargo enclosure such that a lengthwise gap is definedbetween the first forward and aft skirt panels in the lengthwisedirection.
 5. The cargo enclosure of claim 1, wherein the trailing edgeof the first forward skirt panel is positioned aft of the leading edgeof the first aft skirt panel relative to the forward travel directionfor the cargo enclosure such that the first aft skirt panel overlaps thefirst forward skirt panel in the lengthwise direction, and wherein atransverse gap extending between the trailing edge of the first forwardskirt panel and the leading edge of the first aft skirt panel defines anair vent.
 6. The cargo enclosure of claim 1, wherein the first forwardskirt panel defines a compound lateral profile between its leading andtrailing edges.
 7. The cargo enclosure of claim 6, wherein the firstforward skirt panel includes a first lengthwise section and a secondlengthwise section, a lateral profile of the first lengthwise sectiondiffering from a lateral profile of the second lengthwise section suchthat the first forward skirt panel extends further inboard along thesecond lengthwise section than along the first lengthwise section. 8.The cargo enclosure of claim 7, wherein the cargo enclosure includeslanding gear installed or otherwise secured to the bottom wall andwherein the first forward skirt panel defines a transition point atwhich the lateral profile of the first lengthwise section transitions tothe lateral profile of the second lengthwise section, the first forwardskirt panel being installed relative to the landing gear such that thetransition point is located adjacent to an aft end of the landing gear.9. The cargo enclosure of claim 1, wherein the first aft skirt paneldefines a compound lateral profile between its leading and trailingedges.
 10. The cargo enclosure of claim 1, wherein the first aft skirtpanel includes a first lengthwise section and a second lengthwisesection, a lateral profile of the first lengthwise section differingfrom a lateral profile of the second lengthwise section such that thefirst aft skirt panel extends further inboard along the secondlengthwise section than along the first lengthwise section.
 11. Thecargo enclosure of claim 1, wherein each of the first forward and aftskirt panels defines a compound lateral profile between its leading andtrailing edges.
 12. The cargo enclosure of claim 1, further comprising asecond forward skirt panel and a second aft skirt panel, the secondforward skirt panel extending in the lengthwise direction between aleading edge and a trailing edge and being installed along the bottomwall, the second aft skirt panel extending in the lengthwise directionbetween a leading edge and a trailing edge and being installed along thebottom wall aft of the second forward skirt panel relative to theforward travel direction of the cargo enclosure.
 13. The cargo enclosureof claim 12, wherein a lateral gap is defined between the first andsecond forward skirt panels in the lateral direction of the cargoenclosure.
 14. The cargo enclosure of claim 12, wherein the first andsecond forward skirt panels create a converging lateral gap therebetweenas the first and second forward skirt panels extend in the forwardtravel direction towards their respective leading edges.
 15. The cargoenclosure of claim 14, wherein the first forward skirt panel serves asan upwind forward panel and the second forward skirt panel serves as adownwind forward panel when the cargo enclosure is subjected to across-flow directed from its first lateral side edge towards its secondlateral side edge, and wherein, when the cross-flow is directed throughthe lateral gap defined between the first and second forward skirtpanels at their leading edges, the leading edge of the upwind forwardpanel is configured to generate a vortex in association with a firstportion of the cross-flow directed through the lateral gap while asecond portion of the cross-flow is configured to be captured along aninner surface of the downwind forward panel.
 16. The cargo enclosure ofclaim 15, wherein the second portion of the cross-flow exits fromunderneath the cargo enclosure via an air vent defined between thedownwind forward panel and the second aft skirt panel.
 17. The cargoenclosure of claim 12, wherein the trailing edge of the second forwardskirt panel is spaced apart from the leading edge of the second aftskirt panel such that an air vent is defined between the second forwardand aft skirt panels.
 18. The cargo enclosure of claim 12, wherein themulti-panel skit system consists of two pairs of skirt panels, each pairconsisting of a forward skirt panel and an aft skirt panel.
 19. Thecargo enclosure of claim 12, wherein each panel skirt is configured tocreate vortexes at its leading edge from a cross-wind passing thereby.20. A cargo enclosure, comprising: (a) walls defining a cargo space,including a bottom wall; (b) a first forward skirt panel extending alongthe bottom wall of the cargo enclosure generally in the lengthwisedirection of the cargo enclosure between a leading edge and a trailingedge of the first forward skirt panel, with the trailing edge of thefirst forward skirt panel located adjacent to and aligned with orpositioned laterally inboard of a first lateral side edge of the cargoenclosure; and (c) a first aft skirt panel extending along the bottomwall aft of the first forward skirt panel generally in the lengthwisedirection between a leading edge and a trailing edge of the first aftskirt panel relative to a forward travel direction of the cargoenclosure, with the trailing edge of the first aft skirt panel beinglocated adjacent to and aligned with or positioned laterally inboard ofthe first lateral side edge of the cargo enclosure; (d) wherein thefirst aft skirt panel extends laterally inboard as the first aft skirtpanel extends in the lengthwise direction from its trailing edge to itsleading edge such that the leading edge of the first aft skirt panel ispositioned laterally inboard of the trailing edge of the first forwardskirt panel; and further comprising, (e) a second forward skirt panelextending along the bottom wall of the cargo enclosure generally in thelengthwise direction of the cargo enclosure between a leading edge and atrailing edge of the second forward skirt panel, with the trailing edgeof the second forward skirt panel located adjacent to and aligned withor positioned laterally inboard of a second lateral side edge of thecargo enclosure; and (f) a second aft skirt panel extending along thebottom wall aft of the second forward skirt panel generally in thelengthwise direction between a leading edge and a trailing edge of thesecond aft skirt panel relative to a forward travel direction of thecargo enclosure, with the trailing edge of the second aft skirt panelbeing located adjacent to and aligned with or positioned laterallyinboard of the second lateral side edge of the cargo enclosure; (g)wherein the second aft skirt panel extends laterally inboard as thesecond aft skirt panel extends in the lengthwise direction from itstrailing edge to its leading edge such that the leading edge of thesecond aft skirt panel is positioned laterally inboard of the trailingedge of the second forward skirt panel.
 21. The cargo enclosure of claim20, wherein the trailing edge of the first forward skirt panel ispositioned forward of the leading edge of the first aft skirt panelrelative to the forward travel direction for the cargo enclosure suchthat a lengthwise gap is defined between the first forward and aft skirtpanels in the lengthwise direction.
 22. The cargo enclosure of claim 20,wherein the trailing edge of the first forward skirt panel is positionedaft of the leading edge of the first aft skirt panel relative to theforward travel direction for the cargo enclosure such that the first aftskirt panel overlaps the first forward skirt panel in the lengthwisedirection, and wherein a transverse gap extending between the trailingedge of the first forward skirt panel and the leading edge of the firstaft skirt panel defines an air vent.
 23. A cargo enclosure, comprising:(a) walls defining a cargo space, including a bottom wall; (b) a firstpair of skirt panels, comprising: (i) a first forward skirt panelextending along the bottom wall of the cargo enclosure generally in thelengthwise direction of the cargo enclosure between a leading edge and atrailing edge of the first forward skirt panel, with the trailing edgeof the first forward skirt panel located adjacent to and aligned with orpositioned laterally inboard of a first lateral side edge of the cargoenclosure; and (ii) a first aft skirt panel extending along the bottomwall aft of the first forward skirt panel generally in the lengthwisedirection between a leading edge and a trailing edge of the first aftskirt panel relative to a forward travel direction of the cargoenclosure, with the trailing edge of the first aft skirt panel beinglocated adjacent to and aligned with or positioned laterally inboard ofthe first lateral side edge of the cargo enclosure; (c) a second pair ofskirt panels, comprising: (i) a second forward skirt panel extendingalong the bottom wall of the cargo enclosure generally in the lengthwisedirection of the cargo enclosure between a leading edge and a trailingedge of the second forward skirt panel, with the trailing edge of thesecond forward skirt panel located adjacent to and aligned with orpositioned laterally inboard of a second lateral side edge of the cargoenclosure; and (ii) a second aft skirt panel extending along the bottomwall aft of the second forward skirt panel generally in the lengthwisedirection between a leading edge and a trailing edge of the second aftskirt panel relative to a forward travel direction of the cargoenclosure, with the trailing edge of the second aft skirt panel beinglocated adjacent to and aligned with or positioned laterally inboard ofthe second lateral side edge of the cargo enclosure; (d) wherein eachskirt panel of each pair comprises means for generating a vortex when anairflow is directed past the leading edge thereof.
 24. The cargoenclosure of claim 23, wherein the means comprises a sharp inboardlateral profile of a leading section of the skirt panel.
 25. The cargoenclosure of claim 23, wherein the means comprises a camber or shape ofa leading section of the skirt panel.
 26. A multi-panel skirt system fora cargo enclosure, the multi-panel skirt system comprising: (a) a firstforward skirt panel configured to extend along a bottom wall of thecargo enclosure generally in the lengthwise direction of the cargoenclosure between a leading edge and a trailing edge of the firstforward skirt panel, with the trailing edge of the first forward skirtpanel located adjacent to and aligned with or positioned laterallyinboard of a first lateral side edge of the cargo enclosure; and (b) afirst aft skirt panel configured to extend along the bottom wall aft ofthe first forward skirt panel generally in the lengthwise directionbetween a leading edge and a trailing edge of the first aft skirt panelrelative to a forward travel direction of the cargo enclosure, with thetrailing edge of the first aft skirt panel being located adjacent to andaligned with or positioned laterally inboard of the first lateral sideedge of the cargo enclosure; (c) wherein the first aft skirt panel isconfigured to extend laterally inboard as the first aft skirt panelextends in the lengthwise direction from its trailing edge to itsleading edge such that the leading edge of the first aft skirt panel ispositioned laterally inboard of the trailing edge of the first forwardskirt panel.
 27. The multi-panel skirt system of claim 26, wherein theleading edge of the first forward skirt panel is configured to bepositioned further laterally inboard than the trailing edge of the firstforward skirt panel.
 28. The multi-panel skirt system of claim 26,further comprising a second forward skirt panel and a second aft skirtpanel, the second forward skirt panel configured to extend along thebottom wall in the lengthwise direction between a leading edge and atrailing edge thereof, the second aft skirt panel configured to extendalong the bottom wall in the lengthwise direction between a leading edgeand a trailing edge thereof aft of the second forward skirt panelrelative to the forward travel direction of the cargo enclosure.
 29. Amulti-panel skirt system for a cargo enclosure, the multi-panel skirtsystem comprising: (a) a first forward skirt panel configured to extendalong a bottom wall of the cargo enclosure generally in the lengthwisedirection of the cargo enclosure between a leading edge and a trailingedge of the first forward skirt panel, with the trailing edge of thefirst forward skirt panel located adjacent to and aligned with orpositioned laterally inboard of a first lateral side edge of the cargoenclosure; and (b) a first aft skirt panel configured to extend alongthe bottom wall aft of the first forward skirt panel generally in thelengthwise direction between a leading edge and a trailing edge of thefirst aft skirt panel relative to a forward travel direction of thecargo enclosure, with the trailing edge of the first aft skirt panelbeing located adjacent to and aligned with or positioned laterallyinboard of the first lateral side edge of the cargo enclosure; (c)wherein the first aft skirt panel is configured to extend laterallyinboard as the first aft skirt panel extends in the lengthwise directionfrom its trailing edge to its leading edge such that the leading edge ofthe first aft skirt panel is positioned laterally inboard of thetrailing edge of the first forward skirt panel; and further comprising,(d) a second forward skirt panel configured to extend along the bottomwall of the cargo enclosure generally in the lengthwise direction of thecargo enclosure between a leading edge and a trailing edge of the secondforward skirt panel, with the trailing edge of the second forward skirtpanel located adjacent to and aligned with or positioned laterallyinboard of a second lateral side edge of the cargo enclosure; and (e) asecond aft skirt panel configured to extend along the bottom wall aft ofthe second forward skirt panel generally in the lengthwise directionbetween a leading edge and a trailing edge of the second aft skirt panelrelative to a forward travel direction of the cargo enclosure, with thetrailing edge of the second aft skirt panel being located adjacent toand aligned with or positioned laterally inboard of the second lateralside edge of the cargo enclosure; (f) wherein the second aft skirt panelis configured to extend laterally inboard as the second aft skirt panelextends in the lengthwise direction from its trailing edge to itsleading edge such that the leading edge of the second aft skirt panel ispositioned laterally inboard of the trailing edge of the second forwardskirt panel.